Increase security to entryways at home or in the office by installing the SECO-LARM Enforcer Flush-Mount In-Wall Photoelectric Beam Sensor. The transmitter/receiver is designed to fit into a single-gang box for a flush mount application and the beam reflector simply mounts on the wall across from the transmitter/receiver up to 16 feet away. The transmitter/receiver and reflector will not only be attractive, they will not stick out from your wall as other similar plug-in modules will. Beam alignment is adjustable up to 15 degrees horizontally or vertically, making installation even easier. A typical application for this product is to set the beam up across an entryway or hallway in your home, office or retail shop. When the beam is broken, the sensor will turn the yellow LED light on and trigger a normally closed, normally open or common relay output on your alarm system or warning device. This product requires a 12VDC Power Supply, sold separately.